Science Simplified: What Are Dark Matter and Dark Energy?

What Are Dark Matter and Dark Energy?
There’s something amiss in the cosmos. Mysterious influences seem to be stretching the universe apart and clumping stuff together in unexpected ways, but we can’t see or touch them. Scientists call these influences dark energy and dark matter.

Humans have studied the sky for many thousands of years, and in the last century, scientists have really started to understand how the universe moves and changes under the influence of a force called gravity. Gravity affects everything, including not only matter — a scientific term for stuff — but also light. It’s what pulls our bodies into Earth, and it also works over the vast distances between stars and galaxies.